Question

($\frac{5}{ \sqrt{10} + \sqrt{5} }$ + $\frac{4}{ \sqrt{5}-1 }$ ) Totul la a doua : (11 + $\sqrt{40}$ )

Answer 1

[5/(√10+√5)+4/(√5-1)]²:(11+√40)=
=[5(√10-√5)/(√10+√5)(√10-√5)+4(√5-1)/(√5-1)(√5+1)]²:(11+2√10)=
=[5(√10-√5)/(10-5)+4(√5-1)/(5-1)]²:(11+2√10)=
=(√10-√5+√5+1)²:(11+2√10)=
=(√10+1)²/(11+2√10)=
=(√10+1)²(11-2√10)/(11+2√10)(11-2√10)=
=(10+1+2√10)(11-2√10)/(121-40)=
=(11+2√10)(11-2√10)/81=
=(121-40)/81=
=81/81=1